GNSS (global navigation satellite system) pseudo-range multi-path eliminating method based on adaptive filtering

Abstract

A GNSS (global navigation satellite system) pseudo-range multi-path eliminating method based on adaptive filtering includes: based on pseudo-range observed value and carrier observed value of a receiver, acquiring a sequence of code carrier deviation adjacent epoch differential components to obtain a segmented frequency spectrum, and performing sliding window averaging to obtain a continuous spectrum; performing a discrete and adaptive abnormal spectral peak band search to obtain an abnormal spectral peak band frequency-domain range; performing interpolation on the abnormal spectral range to obtain a segmented spectrum with no abnormal peak influence; performing Fourier inversion to obtain corrected code carrier deviation adjacent epoch differential components; performing differencing to obtain a CMCD modified differential sequence, integrating to obtain a CMC modified differential sequence with un-corrected initial phase, and using an initial phase and fluctuation range to perform initial phase modification to obtain a pseudo-range with periodic multi-path eliminated. The method herein is suitable for various observation environments; abnormal spectral peaks under different environments are extracted adaptively; a pseudo-range with no periodic multi-path influence is provided for a user; the error fluctuation influence of GNSS pseudo-ranges under non-ideal observation conditions is greatly decreased.

Description

technical field [0001] The invention belongs to the field of GNSS data processing, and relates to a GNSS multipath elimination method based on adaptive filtering. Background technique [0002] The Global Navigation Satellite System (GNSS for short) is a major international space and information infrastructure, which plays an important role in national economic construction and national defense security. Multipath error is one of the main factors affecting the quality of GNSS receiver observation data. Multipath errors mainly include pseudorange multipath and carrier multipath. Among the multipath errors, especially the existence of pseudorange multipath, it seriously affects the GNSS positioning accuracy. [0003] Multi-path correction is the difficulty of GNSS data processing and accuracy improvement. Compared with modeling errors such as ephemeris error and tropospheric error, multipath error is related to the surrounding environment of the station, the structure and pe...

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Problems solved by technology

[0005] (1) The multipath suppression and noise suppression level of the sliding window temporal averaging technology depends on the selection of the sliding window, and the suppression level is poor when the multipath feature is non-white noise

[0006] (2) The performance of wavelet denoising depends on the selection of wavelet bases and thresholds. In practice, the pre-set wavelet bases and thresholds are not universal enough for different observation data.

[0007] (3) The filtering performance of the FIR filter depends on the cut-off frequency and filter design, and in the case of overlapping of the filtering frequency band and the information frequency band, it is easy to cause the loss of the original information

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